June 08, 2008

Cool painting tech demo o’ the day

Photoshop engineer Jerry Harris is responsible for the application’s painting tools, and he’s always got an eye open for interesting developments in the field of computerized painting.  This morning he passed along a cool demo video of James McCann and Nancy Pollard’s Real-time Gradient-domain Painting technology.


In a nutshell, according to the video, "A gradient brush allows me to paint with intensity differences.  When I draw a stroke, I am specifying that one side is lighter than the other."  Uh, okay… And the video is a little ho-hum until the middle.  That’s when things get rather cool.  Check out cloning/duplicating pixels along a path, plus the interesting approach to painting a band of color.

Posted by John Nack at 10:31 AM on June 08, 2008


  • earth — 11:18 AM on June 08, 2008

    What a useless set of tools. I couldn’t imagine any Photoshop user ever needing this. In fact, i’d like to see a return to yesteryear… those glory days; a single layer and only one undo.

  • Eduardo Moura — 1:28 PM on June 08, 2008

    “Useless set of tools”?? Are you kidding, right? Well, maybe you’re just not the kind of person these tools are for. On the other hand, I can’t wait to see something similar implemented in Ps. From an artist and designer point of view, I can think of a million uses to it –whether it’s to restore something or to add special effects to a composition. My head blows away just thinking of how it would blend with Vanishing Point or Liquify!
    Am I a dreamer?

  • joe — 1:56 PM on June 08, 2008

    I agree with Earth. In fact I only use photoshop because my MAC doesn’t have MS Paint.
    [You should look around online to find a nice used ColecoVision. *THEN* you’d be painting with Real Ultimate Power! –J.]

  • Alex Dukal — 2:26 PM on June 08, 2008

    It looks awesome!
    And I think this could be more interesting than integrating web design tools in PS.
    Is Adobe is planning to integrate this in a future realease?
    [Adobe has certainly been working hard to bring great researchers into the company. We’d like to make it really easy for researchers (whether internal or external) to apply their technology within Photoshop. We’ve added a connection to MATLAB in CS3, but there’s much more we can do. –J.]

  • Klaus Nordby — 2:35 PM on June 08, 2008

    What amazing new-think — thanks for posting it! It’s fascinating and could be immensely useful for many kinds of retouching, so cram this painting feature in CS4. Uh-uh, that’s the upgrade I’m skipping, due to the ghastly ALL-CAPS in the palettes — so getting it in CS5 (which will, according to my prescience, return Adobe to typographic sanity) is soon enough for me. ;-)

  • Peter — 3:15 PM on June 08, 2008

    Wow, nice idea! I guess making this into an intuitive tool isn’t going to be easy…
    Gradients are not that hard to understand. The gradient of a pixel basically says how much change in luminance there is relative to the neighboring pixels, i.e. how much contrast exists between the pixel you are looking at and the ones that surround it. It’s pretty much like derivatives, only for image luminance.
    If you look at an image in gradient domain, it looks like it has gone through an edge detection filter since luminance changes are relatively high at edges, whereas they are very subtle in smooth areas, thus resulting in low gradient values.
    The thing in the video basically lets you paint how much luminance change you want to be there around a given pixel, and the thing they call the “integrator” reverse-engineers that information back into a regular non-gradient-domain image. If the gradient value is high (for example because you painted with a white gradient domain brush), that means there is a lot of change at that pixel, so one side of the brush stroke must be significantly darker than the other. If it weren’t, there would only be a small change and thus a small gradient value.
    The seam carving stuff that was published some time ago uses gradients to determine how important a pixel is in an image. If the gradient value is high, that means that there is a luminance change in that area and it tries to preserve it. If it is low, there is not much change in luminance and thus the pixel can be removed without significant implications for the image.
    I hope that makes the meaning of that “scary” sentence a bit clearer :)

  • imajez — 6:28 PM on June 08, 2008

    That was jaw dropping.
    Those are the guys you should be recruiting to the PS team, not some nerdy colour management type. ;-)
    [A car needs both gas & brakes, young grasshopper. –J.]
    [BTW if you click preview to check your post, it takes an eternity to connect and load page]
    [Yeah, the blogging infrastructure here is in need of a long-overdue tune-up. –J.]

  • jane bush — 3:06 AM on June 09, 2008

    nice demo … thanks for information

  • imajez — 7:29 PM on June 09, 2008

    [A car needs both gas & brakes, young grasshopper. –J.]
    Of course. So does that mean you are grabbing them before someone else does?
    [Yeah, the blogging infrastructure here is in need of a long-overdue tune-up. –J.]
    It gets my vote for the slowest page on the web!

  • Doug Nelson — 1:19 AM on June 10, 2008

    I think something like this would be a brilliant addition. It’s akin to what I’ve been requesting for years, context-aware brushes. Brushes that know what direction they’re being painted at, and where they begin/end, and what is around them. Plus editable post-stroke. I’ve always assumed this would need to be some sort of a vector brush, but it appears they have a different system (displacement maps?).
    Turning this technology into an intuitive tool might take some work. Even the movie was stumbling over how to explain it. And their artist’s example looked better at the halfway point. Obviously they’re engineers, not artists or marketers, so they’re more than forgiven.
    But the roof tile demo alone would make this a must-have tool.

  • Dan — 10:00 AM on June 11, 2008

    [A car needs both gas & brakes, young grasshopper. –J.]
    Obviously, you’ve never played Mario Kart. ;)

  • thin — 6:08 PM on June 11, 2008

    John, the example with the roof tiles: I remember paint shop pro having that feature years ago and now Z-Brush has a similar feature as well. I’m still waiting to have it in photoshop.

  • painting company — 1:50 PM on July 16, 2008

    paint the day!

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